Synthesis Of Carbon-based Metal Electrode Materials And Research In Their Electrochemical Properties

Nanocomposites have attracted widely interesting due to their unique physical, chemical properties and extensive application prospects. The technical development of nanocomposite can help to fabricate the efficient and low-cost electrode materials. The nature of electrocatalysis and the develop of the electrochemical functional device are based on in-depth understanding and research of the mechanism of electrocatalysis for small molecular on metal electrode. In this paper, the newest development in research of electrode substrate materials have been reviewed. The new electrodeposited method is developed to fabricate the hydrogen-evolution materials, and the ordered mesoporous carbon (CMK-3) supported silver nanocatalysts have been prepared through the wet chemical reduction. Meanwhile, the microstructure and electrochmical performance of Ag/C electrode has been evaluated, and the mechanism of formaldehyde electrooxidation on Ag is also discussed. The main content is as follows:1. Fabrication of Ni nanoparticles on ordered mesoporous carbon using an immersion-electrodeposition method. In this paper, a new route have presented to synthesize Ni nanoparticles on the surface of the ordered mesoporous carbon (CMK-3) through an immersion-electrodeposition technique. Transmission electron microscopy (TEM) images indicated that the electrochemically synthesized Ni nanoparticles were homogeneously dispersed on the surface of CMK-3 support with a mean size 35 nm. Liner scanning voltammetry (LSV), cylic voltammetry (CV) and electrochemical impedance spectrum (EIS) technique were employed to investigate the electrocatalytic properties of the Ni/ CMK-3 composite electrode for hydrogen evolution reaction (HER) in alkaline solution, and high electrocatalytic activity for HER was observed. It was stated that the improvement of the electrocatalytic performance of Ni/CMK-3 composite coated GC electrode could be ascribed to the increase in the real surface area of the elctrode as well as to the high dispersion of Ni nanoparticles. Therefore, we report this IE method as a new route to prepare metal/CMK-3 nanocomposites which have potential applications in the catalytic field.2. Silver nanoparticles supported on ordered mesoporous carbon for formaldehyde electrooxidation. The ordered mesoporous carbon (CMK-3) supported silver nanocatalysts have been prepared through the wet chemical reduction by using the reduction of formaldehyde. The electrochemical properties of the Ag/CMK-3 nanocatalysts for formaldehyde oxidation are studied by cyclic voltammerry (CV) and chronoamperometric curves (i-t) in alkaline aqueous solutions. The results show that the peak current density (CV) of the Ag/CMK-3 electrode is 112 mA/cm², above 2 times higher than that of Ag/XC-72 at the same Ag loading (1μg). Furthermore, the i-t curves demonstrate that the Ag/CMK-3 nanocatalysts are efficient and stable electrocatalysts for anodic oxidation of formaldehyde in alkaline solutions. Meanwhile, the roles of the type of carbon substrates, the loading of Ag, and the reduce agents in the formaldehyde oxidation are also investigated.3. The mechanism of formaldehyde oxidation on Ag electrode. The properties of electrocatalytical formadehyde are investegated in acid, alkalescence, and neutral solution through the delicate design of electrochemical experiments. The ability of formaldehyde electrooxidation is related to the concentration of the alkaline aqueous solution. The higher electrocatalytic performance of Ag/C is observed in the solution with the higher value of pH, and the larger active surface area of electrode, the better electrocatalytic properties can be obtained. It is proved that Ag/C electrode have no ability of formaldehyde oxidation in the acid and neutral solution. The mechanism of formaldehyde oxidation in the alkaline aqueous solution is discussed, and the results prove that Ag(OH)_ads plays the bridge role in the formaldehyde electrooxidation.